Does protractor interact with "angular 4" application only over DOM model?

I’m trying to understand which benefits I'll get by using protractor for testing 'angular 4' application through web driver. Is it possible to get access to object model of angular application by protractor? As far as I can see protractor provides access only to DOM model of web application, same as WebDriver with python or java. Some functions of protractor (see clientsidescripts.js) getting access over 'windows.angular', but they are obsolete since there is no more 'windows.angular' in angular 2+.